Dieselgate

[...]

If it overheats, the supply authority has badly f***ed up!

It might blow the service fuse perhaps.

Some flats do not have a gas supply,so rely on electric heating. Traditionally this has been via the dreaded night storage heaters.

Some of these flats have been retro-fitted with systems using traditional wet radiators. The boilers used are electrical, and use 3x4kW immersion heaters. When they were first being installed, the contractors were convinced they would overload the supply, and queried it with the manufacturer. They were reassured it would work; the control system constantly monitors supply voltage, and if it drops too low it starts switching off elements until none are on.

In practice it works well. That loading would be well above what is required for charging a Nissan Leaf, for example. With a smart charging system employing a similar strategy, local distribution won't be the huge problem you are imagining, although I accept that overall capacity in the country will need to improve.

Chris

Reply to
Chris Whelan
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[...]

If you need 10mm2 for a 40A supply, you must live in a huge mansion, in which case you would have a 3-phase supply already!

What! From BS7671 17th Edition, Reference Method C, 4mm2 is rated at 37A.

6mm2 is 47A.

The 12 hour time would be from completely flat; realistically it might be nearer 8 hours, and not many everyday folk spend less than that at home in the night time.

I meant the sizes you quoted for connection to the charging point.

Chris

Reply to
Chris Whelan

Yes, I do realise it is not encouraged, maybe even illegal, but it was safely done without any abstraction !

My main fuses have been unsealed for the last thirty years without comment, although they were resealed when a replacement meter went in. Meter readers are supposed to make a visual safety check, but never notice the lack of seals.

The Merkins are quite up in arms about smart meters and there seem to be genuine concerns as to security and rf radiation IIRC

Reply to
MrCheerful
[...]

Service head.

Chris

Reply to
Chris Whelan
[...]

As I am sure you are aware, you are 'not allowed' to do that!

Up until now it has been impossible to police unauthorised removal of a service fuse; supply authorities turn a blind eye to it unless there is any suspicion of fraud.

With the coming of smart meters, they will know within five minutes if a service fuse is removed or has blown.

Chris

Reply to
Chris Whelan

Would anyone with any sense _want_ to drive to London:?...

Reply to
tony sayer

Still won't be a hanging offence to remove the main fuse to allow safe working on a CU, etc. It's when they notice a big change in metered and paid for electricity that the alarm bells start to ring.

Reply to
Dave Plowman (News)
[...]

UK system will be totally different, and you *can* refuse to have one, although an individual supplier may not want you as a customer.

Chris

Reply to
Chris Whelan
[...]

It's never been allowed to do that.

In theory, the contractor contacts the supply authority to remove the fuse, then contacts them again to replace it.

Of course that hasn't happened up until now because it's not been enforceable. There are some fears within the industry that smart meters will make things more difficult in this respect.

Chris

Reply to
Chris Whelan

Its not just the service cable from street its all cabling, beneath the street

Reply to
steve robinson

Try £2000 or more now if cables running alongside your property not cheap , in Bristol a 30 meter run cost us £12000 we had to dig out the trench they dealt with digging up the road. that was 8 years ago

The network isn't designed for every house to be on 3 phase either.

Reply to
steve robinson
[...]

The cable that runs past your house will already be a 4-core ; 3 phase plus neutral.

The connection from that cable to your house would, in 99% of cases, be all that would need to be upgraded in order to bring all 3 phases into the house.

Chris

Reply to
Chris Whelan
[...]

If the load was the same, why would it matter?

Chris

Reply to
Chris Whelan

Its not just cable size its the length of run, the longer the run the greater the voltage drop so the larger the cable requirement. Plus you have to factor in if hte cables clipped surface , enclosed within other cables covered in insulation or bundled up

A 10mm2 cable dependant on how its installed can be rated between 39 Amps and 63Amps , if its bundled with any other large cables that are likely to be powered up at the same time , you may well have to de rate it

If your looking at armored cable anywhere from 75 to 92 amps

If its multi cored and more than two cores are powered simultaneously you have to lower the capacity of each conductor.

If the cable is bought into the property and run through any insulation , then you have to de rate it

If all your cables are bundled again you have to de rate .

You can't just look on a chart and say that's fine, it doesn't work like that, you have to take into account all the other loadings / factors.

You also need to factor in increased charging capacities as battery capacity increases .

You don't have one outlet in the kitchen , its unlikely given the level of car ownership you will only have one charging portal

Reply to
steve robinson

Easiest option is to install a separate double pole switch so you can isolate the distribution board, a legal requirement if you have long service tails to the distro board . About time it became the norm

Reply to
steve robinson

I wouldn't say f***ed up, the paremeters used to calculate peak and sustained loading requirements on domestic properties have changed dramatically over the years.

When i bought my house we had a 6 way board two lighting (5 amp) two ring main ( 30 amp ) one emersion heater (15 amp) and one cooker socket ( 20 amp) the original board was 4 way with lead sheathed cable.

Your modern boards now run with 3 ring mains (32 each amp) cooker (40 Amp) Showers (45/ 50 amp) Fridge (16 amp) Laundry equipment ( 2x 20 amp) 4 lighting circuits ( 6 amps each)

Reply to
steve robinson

I know. I completed my electrical apprenticeship in 1965, and have IEE 14th,

15th, 16th and 17th editions qualifications.

Further down I stated Reference Method C, as it's the most likely installation method for domestic dwellings; the cable sizes I quoted are based on that. It's very unlikely that voltage drop would ever be an issue in a normal sized house (hence the mansion comment!) Earth loop impedance is more the issue with long runs in domestic situations, but only where supply for portable appliances are concerned.

BTW, there was a fair bit of overhead in the sizes I quoted; that might well be enough for any changes in installation method.

As an aside, it's possible to design a theoretical domestic environment where a 3kW immersion heater would need a 10mm2 T and E supply! That cable size could not physically be connected of course. In practice, you would never meet all those de-ratings in a single house.

Chris

Reply to
Chris Whelan

For urban/suburban areas I expect the future for personal transportation to be electric driverless vehicles, with massive incentives for shared use and similar disincentives for private ownership. Think Uber without the drivers. Since these vehicles will be able to drive themselves elsewhere to be recharged all that is required is suitably equipped parking spaces somewhere near a substation. So the car would go to the charging points rather having to upgrade the distribution network to take the charging points to the car.

Rural dwellers might be able to use a personally owned low-emission vehicle for long distance travel, but if they are venturing into an urban area they would either have to park and swap to a local shared zero-emmision driverless service, or be able to run their own vehicle in a zero-emmision driverless mode for that part of the journey.

Reply to
D A Stocks

If the load drawn exceeds the circuit design limits, and overheats something rather than operates the circuit over-current device, the designer has f***ed up.

The 'parameters used to calculate ... loading requirements' have not changed, only the loads have.

Chris

Reply to
Chris Whelan
[...]

A reg rather than a legality, but yes.

Agree 100%. Can't see why it hasn't happened already.

Chris

Reply to
Chris Whelan

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